Over 20 dead in US polar vortex, frostbite amputations feared

Homes and businesses used record amounts of natural gas to fight the cold, according to financial data provider Refinitiv.

Utilities appealed to consumers to conserve energy to avoid power outages.

In Detroit, General Motors Co suspended operations at 11 Michigan plants to cut natural gas consumption.

Fiat Chrysler Automobiles NV canceled a shift on Thursday at two of its plants.

Snow and ice created treacherous travel conditions, with 26 road collisions reported within two hours on Thursday in eastern Iowa's Johnson County, emergency communications center chief Tom Jones told the Iowa City Press-Citizen.

For the second day in a row, the intense cold and windy conditions forced US airlines to cancel more than 2,000 flights. Chicago was hardest hit, with O’Hare International Airport experiencing over 700 cancellations, according to the FlightAware tracking site.